it's not the feeding people that they're even mad about so much as the freedom of action that a country has when it doesn't rely on trade with other nations for essentials like food and energy
B-B-B-BUT muh COMPARATIVE ADVANTAGE. This isn't PARETO EFFICIENT, and that's against the RULES. (Please ignore the inseparable intertwining of economic and political power and just play along like dupes)
Guevara has a bunch of speeches about this. IIRC, he differentiated between "political freedom", the power of a people to make their own decisions and act on them, and "economical freedom", the power of a people to decide over their production and trade. He argued that a revolution aims for the former; after that, the post-revolution state builds the latter.